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Progress In Electromagnetics Research
ISSN: 1070-4698, E-ISSN: 1559-8985
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RECONSTRUCTION OF EQUIVALENT CURRENTS USING A NEAR-FIELD DATA TRANSFORMATION - WITH RADOME APPLICATIONS

By K. Persson and M. Gustafsson

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Abstract:
Knowledge of the current distribution on a radome can be used to improve radome design, detect manufacturing errors, and to verify numerical simulations. In this paper, the transformation from near-field data to its equivalent current distribution on a surface of arbitrary material, i.e., the radome, is analyzed. The transformation is based on the scalar surface integral representation that relates the equivalent currents to the near-field data. The presence of axial symmetry enables usage of the fast Fourier transform (FFT) to reduce the computational complexity. Furthermore, the problem is regularized using the singular value decomposition (SVD). Both synthetic and measured data are used to verify the method. The quantity of data is large since the height of the radome corresponds to 29-43 wavelengths in the frequency interval 8.0-12.0 GHz. It is shown that the method gives an accurate description of the field radiated from an antenna, on a surface enclosing it. Moreover, disturbances introduced by copper plates attached to the radome surface, not localized in the measured near field, are focused and detectable in the equivalent currents.

Citation: (See works that cites this article)
K. Persson and M. Gustafsson, "Reconstruction of Equivalent Currents Using a Near-Field Data Transformation - with Radome Applications," Progress In Electromagnetics Research, Vol. 54, 179-198, 2005.
doi:10.2528/PIER04111602
http://www.jpier.org/PIER/pier.php?paper=0411162

References:
1. Hansen, J. E. (ed.), Spherical Near-Field Antenna Measurements. No. 26 in IEE electromagnetic waves series, and Peter Peregrinus Ltd., Stevenage, No. Spherical Near-Field Antenna Measurements. 26 in IEE electromagnetic waves series, UK, 1988.

2. Yaghjian, A. D., "An overview of near-field antenna measurements," IEEE Trans. Antennas Propagat., Vol. 34, No. 1, 30-45, 1986.
doi:10.1109/TAP.1986.1143727

3. Rahmat-Samii, Y., L. I. Williams, and R. G. Yaccarino, "The UCLA bi-polar planar-near-field antenna-measurement and diagnostics range," IEEE Antennas and Propagation Magazine, Vol. 37, No. 6, 16-35, 1995.
doi:10.1109/74.482029

4. Hanfling, J., G. Borgiotti, and L. Kaplan, "The backward transform of the near field for reconstruction of aperture fields," IEEE Antennas and Propagation Society International Symposium, Vol. 17, 764-767, 1979.

5. Corey, L. E. and E. B. Joy, "On computation of electromagnetic fields on planar surfaces from fields specified on nearby surfaces," IEEE Trans. Antennas Propagat., Vol. 29, No. 2, 402-404, 1981.
doi:10.1109/TAP.1981.1142563

6. Lee, J. J., E. M. Ferren, D. P. Woollen, and K. M. Lee, "Near-field probe used as a diagnostic tool to locate defective elements in an array antenna," IEEE Trans. Antennas Propagat., Vol. 36, No. 6, 884-889, 1988.
doi:10.1109/8.1192

7. Varadan, V. V., Y. Ma, V. K. Varadan, and A. Lakhtakia, "Scattering of waves by spheres and cylinders," Field Representations and Introduction to Scattering, 211-324, 1991.

8. Woodworth, M. B. and A. D. Yaghjian, "Derivation, application and conjugate gradient solution of dual-surface integral equations for three-dimensional, multi-wavelength perfect conductors," Progress In Electromagnetics Research, Vol. 5, 103-129, 1991.

9. Sarkar, T. K. and A. Taaghol, "Near-field to near/far-field transformation for arbitrary near-field geometry utilizing an equivalent electric current and MoM," IEEE Trans. Antennas Propagat., Vol. 47, No. 3, 566-573, 1999.
doi:10.1109/8.768793

10. Ström, S., "Introduction to integral representations and integral equations for time-harmonic acoustic, electromagnetic and elastodynamic wave fields," Elsevier Science Publishers, 37-141, 1991.

11. Balanis, C. A., Antenna Theory, second edition, John Wiley & Sons, New York, 1997.

12. Jones, D. S., Acoustic and Electromagnetic Waves, Oxford University Press, New York, 1986.

13. Strang, G., Introduction to Applied Mathematics, Wellesley- Cambridge Press, Box 157, Wellesley, MA 02181, 1986.

14. Kress, R., Linear Integral Equations, Springer-Verlag, Berlin Heidelberg, 1999.

15. Anton, H., Elementary Linear Algebra, 7 edition, John Wiley & Sons, New York, 1994.

16. Jackson, J. D., Classical Electrodynamics, second edition, John Wiley & Sons, New York, 1975.


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